Audible signal device



-Feb.1v, 194z. A. L. am am "2,273,688

AUDIBLE S IGNAL DEVICE Feb. 17,4 1942. A. L. BOLZ l-:TAL 2,273,688

` AUDIBLE SIGNAL DEVICE Filed oct'. '7. 1939 2 Sheets-Sheet 2 H 0 V Hx E EU N DE R EE 0 R BW T Af A H C m. .Hv y m, B .n w

Patented Feb. 17, 1942 AUDIBLE. SIGNAL DEVICE Andrew L. Bolz, New York, N. Y., Harold- A. Bredehoft, Millington, N. J., and Charles F.

Wiebusch, New York, N. Y., Bell Telephone Laboratories,

assignors to Incorporated,

New York, N. Y., a corporation of New York Application October 7, 1939, Serial No. 298,408

6 Claims.

This invention relates to audible signaling devices of the type generally known as telephone ringers and particularly to heavy duty ringers intended for use under severe operating conditions and in localities requiring a sound signal of relatively great intensity.

The object of this invention is to simplify and otherwise improve the construction of telephone ringers whose sound emitting elements are equipped with mechanical `sound ampliers in the form of resonators.

'Ihis object is attained in accordance with one feature of the invention by housing the electromagnetic portion of the ringer in an enclosed compartment comprising a die-cast, or molded base and a similarly constructed cover, the latter being secured to the base by means of screws which are threaded into tapped bosses projecting from the front face of the base. A

A more pertinent feature of the invention resides in casting the sound resonatorsintegral with the base which supports the electromagnetic structure of the ringer.

These and other features of the invention will be readily understood from the following detailed description made `with reference to the accompanying drawings, in which:

, Fig. 1 is a front elevation of a ringer designed` tion of thearrows;

Fig. 4 is a front elevation of the mounting base stripped of the ringer equipment;

Fig. 5 is a side elevation of the base illustrate y in Fig. 4; and` l Fig. 6 is a rear elevation of the mounting base. The subject-matter disclosed in the drawings may be considered to consist of two main parts, namely, the ringer per se, and the housing there-v for which consists of the mounting base and cover.

and will be followed by a detailed description of the mounting base. p

The ringer per se is built along well-known lines and consists essentially of a pair of magnet The rst description will be directed primarily to the construction of the ringer per se coils,k a permanent magnet, an armature, a clapper rod secured to the armature and a pair of gongs between which the clapper rod functions when the magnet coils are energized to cause the gongs to be alternately struck.

Referring now to the drawings and particularly to Figs. land 2, the ringer consists of a U- shaped permanent magnet II whose extremities are bridged by a cross-bar I2 of magnetic material. The cross-bar I2 may be secured to the permanent magnet ends in any suitable manner, preferably by welding. The cross-bar I2 serves as a support for the spaced cores I3 and I4 of the ringer electromagnets. Each core is provided with a winding such as I9and 2li, and passes through an aperture in the insulating plate I5 which serves` as a spoolhead and is common to the two windings I9 and 2l) of the ringer. The lower ends of the cores I3V and I4 are drilled and tapped to receive machine screws I6 which serve to secure the electromagnetic structure to the mounting base, as will appear more fully in a later description.

The plate I5 is a comparatively stiff strip of insulating material, such as phenol fibre and has its front edge provided with a series of spaced notches into which the free end of an armature biasing spring I'I nts. By moving the free end of the biasing spring II from one notch to another the biasing torque on the armature I8 may be adjusted, the other end of the spring I1 being staked or otherwise fixed to a depending integral arm 25 of the armature.

The coils I9 and 20 are Wound on the cores I3 and I4 respectively, between the strip I5 and the circular spoolheads 2l and 22, respectively, the latter being apertured to permit them to be slipped over the shank and against the head of their respective cores. The upper ends of the cores I3 and I4 project beyond the upper face of the spoolheads 2I and 22, respectively, and extend through circular apertures in the non-magnetic yoke 23. The dimensions of the upper core ends and of the yoke apertures are such that the yoke is held firmly on the core ends.

The yoke 23, though substantially totally coniined between the two side legs of the permanent magnet I I, is provided with a small integral projection extending from each of the rear corners thereof which abut against the rear edges of the permanent magnet I I. At each side of its midsection the yoke 23 is provided with a depending lug, one of which is shown in broken lines behind the armature lug 25, which lugs are provided with alignedv circular holes through and beyond is provided with a small circular aperture through each of which a protruding end of the pin 24 extends and is then staked. In this `manner the armature IS is supported by the yoke 2.3 through the agency of the pin 24 which sfree to rotate in the small apertures in the yoke lugs.

The rear integral extension or `lug 26 of `armature I'B is of greater length than the corresponding front lug 25 and terminates in an outwardly projecting portion 2 (Fig. 2) to -which the clapper rod 28 is staked. At its lower extremity, the rod 2S carries a striker ball 29.

When the windings i9 and 2!! of the ringer areA energized the armature i8 is caused to operate in the well-known manner. The olapper lrod 28 is correspondingly actuated and the striker ball '2Q caused Vto strike the'gongs 30 and `3| alternately. Ihe manner in which the gongs 'are mounted will appear from the following description directed to the construction of the mounting base and the integrally formed resonators.

The mounting base which serves as a support for the electromagnetic structure and bells of the ringer is die-cast, or molded of aluminum or some other suitable alloy, and consists essentially of a substantially rectangular wall 3'! and a pair 'I 4of diverging neck-like extensions '35 and 35, each of which terminates in a substantially hemispherical dome-like portion 5G or 6l. The wall 37 is provided with two straight sidewalls 38 and 39, a slightly arcuate upper wall 40 and a similarly shaped lower wall 6i, the latter being open at S3, 94 and 95. The outlet 95 communicates with a compartment il formed by an inclined forwardly projecting depression whose upper edge or boundary constitutes a shoulder which, in eiect, denes the lower edge of a compartment whose upper boundary is the arcuate wall mi. This upper compartment serves to house a condenser 52 which is utilized in the ringer circuit. The compartment effected by boss l2 constitutes a receptacle or enclosure for the wires of theringer circuit which pass by way of the neck portion 3%, through the aperture 53 in boss 42, to be eventually terminated at the .terminal strip 50, to be more fully referred to hereinafter.

On either side of the compartment gli and located near the lower end of the wall 3l, is formed a forwardly extending inclined boss 42 or 43, each of which has integrally formed therewith a pedestal or shelf-like extension 8l or 82. The extent to which the pedestal portions extend beyond the front edge of the side walls, as well as the depth of the side walls are clearly disclosed "in Fig 5. Each of the pedestal portions is provided with a circular hole 96 (Fig. 3) through which mounting screws -li pass to engage and securely fix the electromagnetic structure of the ringer, as will be explained more fully later.

On each side of the rear wall 37 and extending forwardly therefrom, is a series of substantially cylindrical bosses 45, d8 and "i5 whose purposes will be described presently. The bosses 48 serve to support the terminal strip 5t which is Secured t0 the bosses by means of screws 49, the said bosses being tapped to receive the screws.

Interposed between the upper faces of the bosses 48 and the terminal strip 50 are located the ends of a bow spring which is arched in such a manner as to press against the condenser 52 and hold it rmly against the face of the wall 31, the said condenser being further conned between the shoulder Sl and the upper wall 40 of the base.

The bosses 'i5 are tapped for the reception of the cover screws 15 which serve to secure the cover '7.7 rigidly to the base. The purpose of the bosses 45 will appear from the description having -to do .with the mounting of the electromagnetic .structure on the pedestal portions 8l and 82.

The bosses BG are relatively short and merely l strengthen the apertures through which screws,

used in Amounting the base on a support, pass.

In mounting the electromagnetic structure on the base, the cross-bar i2 is seated on the pedestal projections 8l and 82 with the apertures thereof in alignment. The screws l5 are then passed through these apertures and screwed into the tapped ends of the cores I3 and M. The electromagnetic structure is thus held in an upright position, and the height of the bosses 45 is such that the rear edge projections of yoke 23 abut against the faces of the Vbosses 915. Thus the electromagnetic structure is xedly held in spaced relation to the inner face of the rear wall 37 of the mounting base.

As clearly disclosed in Figs. 5 and 6, the outside walls of the neck portions 35 and 36, in effect, constitute continuations of the side walls 3G and 38, respectively, and at their lower ends, these outside walls are continued or extended in an arc -of a circle for substantially 120 degrees, though this length of arc is not critical. These curved flanges constitute apron-like extensions 811 and from the dome-like portions 6I and EU, respectively, and serve as guards against the ingress of moisture or other foreign material which might cause deterioration of the ringer wiring. It will also be noted that the side wall edges and the edges of the guards 64 and 85 are in the same plane, so that any pressure which may be applied to the dome-like portions 6D and Si during the mounting of the gongs thereon, or at any other time, will not cause any undue stress on the neck-like portions 35 and 3B which might cause them to break,

The dome-like portions E@ and .ii are substantially hemispherical in shape, having the same general contour as the gongs they support. The portions Si) and SI constitute sound resonators for the bells 3l and 3i), respectively and are each provided with a boss 68 located at the apex of the dome and tapped to receive the gong mounting screws 69. The depth of the boss E8 is such as to space the gong from its respective resonator a predetermined distance. The edge or rim of each of the resonators is fianged to effect a circular ledge 65B upon which is force-fitted a circular metal disc t5 which constitutes a cover for the resonator. Each resonator is provided with a pair of diametricaliy disposed substantially triangular-shaped openings 5S and 5i of predetermined dimensions. These openings, or apertures are so located on the resonator wall that the rear edge thereof is in substantial alignment with the rim of the gong with which the resonator functions. The apertures 6i; and l are also so located that when the electromagnetic structure is secured to the base, the inner openings are positioned opposite the points on their respective gongs at which the striker ball 29 engages the gong when the ringer coils are energized. This is to insure maximum tone amplication. n l

After mounting the ringer structure on the pedestal portions 8| and 82 of the base, the cover 11 may be fitted over the side and end walls of the base and the screws 'I6 screwed into the tapped bosses 15. The cover rim is so constructed that a groove 99 is formed into which the edges of the side and end walls of the base t. If desirable a gasket may be used at this point as a seal. The lower face of the cover at its rear mid-point is provided with an opening through which the clapper rod 28 extends. y

Should it be desirable, the rear wall of channel 9|]v may be apertured and provided with a bushing through which the clapper rod 2`8 may pass vand thence be passed downwardly through the opening 95 in the rear of the lower arcuate edge of the base. This. would serve to prevent moisture from entering the housing by way of the aperture through which the clapper rod passes.

What is claimed is:

1. In combination, a telephone ringer having a bell, and a mounting for said ringer comprising a casting to which said ringer is secured and having a hemispherically shaped portion supporting said bell and constituting a resonator therefor.

2. In combination, a telephone ringer having a bell, a resonator formed with a resonating air chamber, said resonator having a wall of substantially the same contour as the bell, means for mounting said bell on said resonator in spaced telescopic relation, a base formed integral with said resonator providing means for mounting said ringer thereon and a cover for the mouth of the resonating chamber removably associated withk said resonator.

3. A ringer mounting comprising a base having an integral pedestal to which said ringer is secured, a pair of resonators cast integral with said base and means for mounting the ringer gongs on said resonators in telescopic relation.

4. A support for a ringer having an electromagnetic operating mechanism and a pair of cupshaped gongs, comprising a base having a pair of pedestal portions cast integrally therewith for supporting said electromagnetic operating mechanism, a pair of arms lcast integral with said base and diverging therefrom below said pedestal portions and terminating in substantially hemispherical portions arranged to support said cupshaped gongs in telescopic relation thereto.

5. A support for a ringer having an electromagnetic operating mechanism and a pair of cup-shaped gongs, comprising a base having integral pedestal portions upon which said operating mechanism is supported and a pair of resonators cast integral with said base and having the same general contour as said gongs and provided with two small openings in the walls thereof, substantially degrees apart, said resonators constituting a support for said gongs and adapted to mount said gongs so as to locate the resonator openings near the mouths 'of said gongs.

6. A mounting for a gong type telephone ringer comprising a base having a pair of shelf-like projections cast integral therewith and extending outwardly therefrom, to which one end of the ringer may be secured vin spaced relation to said base, a pair of bosses cast integral with said base application of pressure on said dome-like por-V tions during the mounting of the gongs thereon.

ANDREW L. BOLZ. HAROLD A. BREDEHOFT. CHARLES F. WIEBUSCH. 

